The present invention relates to capacitors and supercapacitors. More particularly, the present invention relates to capacitors and supercapacitors having at least one component containing a carbon product. The present invention further relates to methods of making capacitors and supercapacitors.
A capacitor is typically a device for introducing capacitance into a circuit. In general, a capacitor consists of two metal plates insulated from each other by a dielectric. The capacitance of a capacitor can depend primarily on the shape and size of the capacitor and upon the relative dielectric constant of the medium between the plates.
There are a variety of different types of capacitors. For instance, there are electric double layer capacitors which contain a gasket, a pair of polarized electrodes made of activated carbon particles and disposed in the gasket, a separator disposed between the polarized electrodes for preventing electrons from moving between the electrodes, and a pair of current collectors mounted respectively on the opposite surfaces of the polarized electrodes. The electrodes can be made as paste electrodes from a concentrated slurry of a powdery or particulate activated carbon and an electrolyte. These double layer capacitors are sometimes referred to as supercapacitors or ultracapacitors.
There is always a demand for improved capacitors which have a higher ability to store energy, in other words, a higher capacitance. There is also a need to lower the internal resistance within the capacitor. There is yet another need to lower the internal current leakage. Also, manufactures are always interested in processes which can reduce production costs such as by simplifying the overall manufacturing of capacitors.
A feature of the present invention is to provide an electrode which preferably has the ability to promote a higher capacitance once incorporated into a capacitor.
Another feature of the present invention is to provide an electrode that promotes lower internal resistance once incorporated into a capacitor.
An additional feature of the present invention is to provide electrodes which are easier to manufacture.
A further feature of the present invention is to provide electrodes with a lower DC leakage.
Additional features and advantages of the present invention will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention will be realized and obtained by the elements and description particularly pointed out in the written description and appended claims.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the present invention relates to an electrode. The electrode contains at least one modified carbon product and at least one binder. The modified carbon product is at least one carbon product having attached at least one organic group.
The present invention further relates to a capacitor which contains at least one electrode of the present invention.
The present invention further relates to a method to increase the capacitance of a capacitor by using at least one electrode containing at least one modified carbon product.
The present invention further relates to a method to lower internal resistance of a capacitor by using at least one electrode containing at least one modified carbon product.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention, as claimed.
FIG. 1 is a schematic drawing of a capacitor structure of the present invention.